Elon Musk recently announced on Twitter that Tesla would be discontinuing the 75 kWh variants of the Model S and Model X. The two models will now be offered only in the 100 kWh and 100 kWh Performance versions. The smaller battery-capacity car is up for sale only until Sunday night. Does this mean this mean that Tesla will begin using its new battery cells in the Model S and Model X, a move that could eventually make them track worthy?